40. From the passage we can infer that
Johnson would be very ____ after he read those people’s letters.
A. miserable B.
glad C. surprised D. said
B
Both
warm-blooded and cold-blooded desert animals have ways to escape the desert
heat. Warm- blooded desert animals, such as rats and mice, rest during the day,
often staying in cool underground burrows. At night they search for
food. Animals that are out during the day, such as cold-blooded lizards and
snakes, are active only for short periods. As their body temperature rises, these
reptiles(爬行动物) move
into the shade in order to cool down. In the early evening, when the sun grows
weaker, the reptiles become more active and begin their search for food again.
Getting
enough water to survive is a major problem for all desert animals. Some desert
animals, like desert birds, manage to find water holes. Other desert animals,
such as the kangaroo rat and the related jerboa, get water only from the food
that they eat. Because these animals eat mainly dry seeds, they must survive on
a tiny amount of water.
Most deserts
have only a small number of frogs and toads because these animals must be near
water to survive. Yet even these creatures have adapted(适应) to desert conditions. When small
amounts of water collect in temporary streams, the desert-living frogs and
toads become active. After a rainfall, they lay their eggs. The eggs grow into
tadpoles in a few days and into adults in just four weeks. When the puddles(水坑) dry up, the adult frogs or toads
dig into the ground. Their metabolism(新陈代谢) slows, and they stay beneath the ground until the next rain, which
may be as good as a year away. Until then, their bodily activities continue at
a reduced rate.
The camel -
often called the ship of the desert - is one of the most successful desert
animals. Camels can go for long periods without water, but eventually they must
drink. When water becomes available to them after a long drought, they may
drink 95 liters of water or more. When water is not available, what helps
camels survive the desert heat is the fat stored in their humps(驼峰). A camel’s hump contains about
12 kilograms of fat. Fat is rich in hydrogen. As the fat is digested, hydrogen
from the fat combines with oxygen in the air that the camel breathes. The
result is H2O, or water. Each kilogram of fat that a camel digests produces
about a liter of water.